The present invention relates to office equipment such as printers and copiers, and specifically relates to replaceable cartridges, such as containing marking material such as ink or toner, which are installable in such equipment.
In the office equipment industry, for every model of equipment, such as a copier, printer, facsimile, or multifunction device (all of the above being, to some extent, xe2x80x9cprintersxe2x80x9d) there is typically one or more parts which are intended to be removed and replaced readily by an end user. Typical among such parts is a supply cartridge for holding marking material used in the printing process, such as toner or liquid ink. Users purchase or otherwise obtain replacement cartridges and install them in their machines as needed.
It is common that a manufacturer or vendor will make available a xe2x80x9cplatformxe2x80x9d of equipment, meaning a basic hardware structure on which a family of models is based. For instance, a basic print engine may be available in a copier version and a printer-only version; different basically-similar models may be designed to operate at different speeds; or different models may be adapted to use different types of marking material, such as color or MICR ink or toner. Some cartridges, particularly those containing marking material, may be inadvisable to use with different models within the same platform; however, in the interest of minimizing costs, it is desirable to make the cartridges for various models generally physically similar.
U.S. Pat. No. 4,611,730 discloses a toner replenishing device comprising a largely cylindrical container which is intended to rotate around an axis within a printer. Around the circumference of the cylinder is a set of gear teeth which is engaged by a drive gear in the printer. It is evident from the description that the gear teeth are intended to be provided around the entire cimcumference of the container.
U.S. Pat. No. 5,289,242 discloses a digital printer which is capable of printing in both regular and MICR modes. The MICR-material version of the marking material cartridge is distinguished by a conductive label which completes a test circuit when the cartridge is installed. When the test circuit is completed, the control system of the printer is advised that the MICR cartridge has been installed.
U.S. Pat. Nos. 5,807,005 and 6,009,285 disclose a digital printer in which a marking material cartridge includes an xe2x80x9cencoder wheelxe2x80x9d pivotably attached thereto, and which is caused to rotate upon installation of the cartridge. The encoder wheel includes a set of xe2x80x9cdigital indicatorsxe2x80x9d which are caused to be sensed in sequence as the wheel rotates. The data collected by the printer from the encoder wheel controls the printer, including causing the printer to lock if a xe2x80x9cwrongxe2x80x9d type of cartridge is installed.
U.S. Pat. No. Des. 379,194, which relates to the Xerox(copyright) 5614(trademark) copier, released in 1995, shows an example of a cartridge in a system whereby different versions of the same platform each use a different version of a supply cartridge. In this case, each version uses a supply cartridge where a small indentation is in a different position on the cartridge.
According to one aspect of the present invention, there is provided a removable cartridge suitable for use in a printing apparatus, comprising means defining a plurality of engagement structures, the engagement structures arranged around a circle, the plurality of engagement structures together occupying no more than half a circumference of the circle.
According to another aspect of the present invention, there is provided a method of operating a set of printing machines, each printing machine using a removable cartridge. For a first subset of printing machines, a first population of cartridges is provided, each of the first population of cartridges including means defining a plurality of engagement structures, the engagement structures arranged around a circle. For a second subset of printing machines, a second population of cartridges is provided, each of the second population of cartridges including means defining a plurality of engagement structures, the engagement structures arranged around a circle. For each of the first and second population of cartridges, the plurality of engagement structures together occupy no more than half a circumference of the circle. The engagement structures of the first population of cartridges are physically distinguishable from the engagement structures of the second population of cartridges.